Search results for "COMPRESSION"

Experimental „Luxury Perfusion” in the Cerebral Cortex of the Cat

1968

Publisher Summary Preliminary studies have been performed, on the changes of cortical rCBF (Krypton- 85 Beta clearance technique) in response to a localized pressure applied to the cerebral cortex (suprasylvian gyrus) of 8 cats under Nembutal anesthesia (30 to 40 mg/kg bodyweight). No change in rCBF is found at regions as distant as the contralateral hemisphere. The increase of rCBF at the compressed site, during the compression, seems to be more marked in animals with higher blood (i.e. perfusion) pressure, and may be absent in cats with blood pressure of about 80 mm Hg. The augmentation of rCBF around the compressed area during the compression is always very marked, and after some time fl…

Data Compression Approach for Long-Term Monitoring of Pavement Structures

2019

Pavement structures are designed to withstand continuous damage during their design life. Damage starts as soon as the pavement is open to traffic and increases with time. If maintenance activities are not considered in the initial design or considered but not applied during the service life, damage will grow to a point where rehabilitation may be the only and most expensive option left. In order to monitor the evolution of damage and its severity in pavement structures, a novel data compression approach based on cumulative measurements from a piezoelectric sensor is presented in this paper. Specifically, the piezoelectric sensor uses a thin film of polyvinylidene fluoride to sense the ener…

A Fast GPU-Based Motion Estimation Algorithm for H.264/AVC

2012

H.264/AVC is the most recent predictive video compression standard to outperform other existing video coding standards by means of higher computational complexity. In recent years, heterogeneous computing has emerged as a cost-efficient solution for high-performance computing. In the literature, several algorithms have been proposed to accelerate video compression, but so far there have not been many solutions that deal with video codecs using heterogeneous systems. This paper proposes an algorithm to perform H.264/AVC inter prediction. The proposed algorithm performs the motion estimation, both with full-pixel and sub-pixel accuracy, using CUDA to assist the CPU, obtaining remarkable time …

Reversible Tuning of Ca Nanoparticles Embedded in a Superionic CaF2 Matrix

2019

Controlling the size and shape of metallic colloids is crucial for a number of nanotechnological applications ranging from medical diagnosis to electronics. Yet, achieving tunability of morphological changes at the nanoscale is technically difficult and the structural modifications made on nanoparticles generally are irreversible. Here, we present a simple nonchemical method for controlling the size of metallic colloids in a reversible manner. Our strategy consists of applying hydrostatic pressure on a Ca cationic sublattice embedded in the irradiated matrix of CaF2 containing a large concentration of defects. Application of our method to CaF2 along with in situ optical absorption of the Ca…

Analisi Sperimentale del Comportamento Ciclico di Elementi in Calcestruzzo a Bassa Resistenza Confinati con FRCM

2013

Vengono riportati i principali risultati di una campagna sperimentale finalizzata alla caratterizzazione della risposta sotto carichi assiali ciclici di colonne di calcestruzzo a bassa resistenza con sezione circolare, quadrata e rettangolare, rinforzate con fibre di carbonio immerse in matrice cementizia (CFRCM). Sono state condotte prove di compressione assiale su 30 campioni di altezza 600 mm, 10 a sezione cilindrica di diametro 300 mm, 10 quadrata di lato 200 mm, e 10 rettangolare di lato 200x400 mm. Le prove sono finalizzate a indagare gli effetti del carico ciclico, della forma della sezione, del raggio di curvatura degli spigoli e del numero di strati di tessuto di rinforzo sul legam…

Volumetric changes of articular cartilage during stress relaxation in unconfined compression

2000

The time-dependent lateral expansion and load relaxation of cartilage cylinders subjected to unconfined compression were simultaneously recorded. These measurements were used to (1) test the assumption of incompressibility for articular cartilage, (2) measure the Poisson's ratio of articular cartilage in compression and (3) investigate the relationship between stress relaxation and volumetric change. Mechanical tests were performed on fetal, calf, and adult humeral head articular cartilage. The instantaneous Poisson's ratio of adult cartilage was 0.49+/-0.08 (mean+S.D.), thus confirming the assumption of incompressibility for this tissue. The instantaneous Poisson's ratio was significantly …

Does Optimal Volume Fraction in Percutaneous Vertebroplasty Prevent Cement Leakage?

2018

Cerebral spinal fluid flow, venous drainage and spinal cord compression in achondroplastic children: impact of magnetic resonance findings for decomp…

2001

In order to investigate the diagnostic properties of MRI of the brain and spine in achondroplastic children with regard to decompressive surgery, 25 patients were examined by conventional morphological and by "functional" imaging of CSF flow and magnetic resonance angiography (MRA) of the veins and sinuses at the cranial base following a special protocol. The results were compared to those from age-matched controls and were correlated with each other and retrospectively with the neurological findings. Measurements of distances and angulations at the cranio-cervical junction (CCJ) from MR scans showed similar values to those from conventional radiographs and CTs and thus can be used without …

A fatal iatrogenic right vertebral injury after transoral odontoidectomy and posterior cervical stabilization for a type II odontoid fracture.

2014

Abstract The authors present a singular case of an iatrogenic right vertebral artery injury, involving a 67 year-old man, who reported a type II odontoid fracture (Anderson and D'Alonzo Classification) and posterior atlantoaxial dislocation following a road traffic accident. A small injury involving the right vertebral artery occurred as a consequence of transoral odontoidectomy and posterior cervical stabilization. It was caused by bone spicules of spinal origin and their presence was confirmed by the histological section of the right vertebral artery at the level of C1–C2. The case confirms how iatrogenic vertebral artery injuries during cervical spine surgery may be potentially lethal, e…

Analog joint source-channel Multiple Description coding scheme over AWGN parallel channels

2011

We propose a low complexity analog joint source channel coding Multiple Description (MD) scheme for transmitting the symbols of a Gaussian source across a pair of independent AWGN channels. The outputs of these channels have each a separated receiver, whereas a third receiver has both outputs available. At the transmitter side, a pair of bandwidth-reduction analog mappings are used for joint source-channel coding. The presented scheme has the inherent advantage over digital MD schemes based on separation, that coding and decoding can be performed by using a single-letter (or symbol), a strategy that is very suitable for applications where latency originated by the digital compression and th…